This invention relates to a method and apparatus for replacing any of a plurality of different types of railroad car door roller assemblies which are conventionally operatively positioned so as to rotatably carry a railroad car door for movement on any of a variety of different types of cooperating tracks.
Railroad car door assemblies which are commonly used today, generally, are the "plug" type of car door assembly. In this type of car door assembly, the railroad car door, when moved into position adjacent the opening in the side of the railroad freight car, is moved transversely inwardly into the opening to "plug" the opening. When the door is to be opened, the car door is moved transversely outwardly so that the door may move laterally along the outer surface of the side of the box car. The bottom edges of the car door are operatively secured to a plurality of roller assemblies which roll along suitable tracks which are mounted by the floor adjacent the door opening and adjacent the exterior surface of the railroad freight car.
Generally speaking, there are at least four different types of railroad car door roller assemblies which are commonly used, although there are still other types. The reason for the use of different types of car door assemblies is that there are several different manufacturers for railroad freight cars and each manufacturer has its own type of car door roller assembly and cooperating track. A large number of railroad car door roller assemblies in use today are similarly constructed as the roller assembly generally includes a housing having a pair of end sections, each of which is adapted to rotatably carry a roller member which is rotatable and movable along a cooperating track. The end sections are conventionally rigidly interconnected by an intermediate section. An upright aperture is provided in the intermediate section. Various types of guides are provided on the housing so as to cooperate with the roller assembly and the track in order to guide the movement of the roller assembly along the track to thereby assure that the car door moves properly along the track.
The upright aperture generally provided in the intermediate connecting section is constructed and arranged to rotatably carry one downwardly projecting end of an arm having an opposite, upwardly projecting end which is also rotatably carried in the lower portion of the car door itself. The pivoting arms permit the plug type door to be moved slightly inwardly and outwardly of the opening in the freight car.
While the different types of car door assemblies being commercially used today are generally quite satisfactory for their given purpose, one disadvantage common to each of the known devices is their lack of versatility. In other words, one manufacturer's roller assembly cannot be used with another manufacturer's car door and/or track assembly. In other words, each manufacturer generally supplies a car door roller assembly which is designed to be used only with its own equipment and not with another manufacturer's equipment. As a result, a railroad yard must have its shop stock each of the different types of roller assemblies being used so as to be sure that there are sufficient car door roller assemblies available for replacement of various types of railroad freight cars which pass through a railroad yard. The track and the door are considered to be a permanent part of the railroad car. Thus, even if a railroad decided to standardize on one type of railroad box car, using a given type of car door, a given type of roller, and a given type of track, since it is well known that a freight train is normally made up of a great variety of freight cars from different railroads, as a practical matter, there is no advantage for one railroad to attempt to standardize on its freight cars, car doors, car door roller assemblies or car door tracks. Thus, a repair shop in a railroad yard of a given railroad is required to maintain an inventory of various railroad car door roller assemblies for replacement of damaged or broken car door roller assemblies.
Clearly, it would be highly advantageous to provide a method and/or an assembly by which at least about four different types of car door roller assemblies could be replaced by using a basic repair kit which is readily adapted to being used in a railroad yard for replacing broken or damaged car door roller assemblies.